I have been playing the game for about 3 hours now and I can tell you one thing for sure: Exploration is barely toned down at all. It's simply been streamlined to make it easier. The only time you don't explore much is on the first planet when you are surrounded by a bunch of marines. So if you don't like exploration, do NOT buy this game.
Graphically, the game is gorgeous. It's art really just blows me away (I'm playing it on a 42" Plasma). The environments are just completely stunning. This isn't as much true about the first planet (Which is full of sci-fi futuristic technology), but after that the standard gorgeous and unique Metroid environments set in.
As far as controls, there is no denying that these completely blow dual analog away. I am just stunned by how much I like them. I actually enjoy the controls more than mouse and keyboard. That's not to say they are quite as good for shooters as mouse and keyboard, but they are a complete blast.
With these new controls, there is certainly more combat than in past titles, but believe me: It has in no way overwritten the adventure aspects of the game. Nor has it destroyed the feeling of desolation and solitude (and wonder) you get from being on these amazing alien planets with no help. As I said, the first hour or so of the game is different, but after that you'll find yourself thrown into the same Prime formula as past games. However, that formula has been tweaked and perfected to really balance it out better. There are still thousands of things to scan per level, and you are still going to need to backtrack a lot, but the ship makes that much faster and easier. If I agree with any review entirely, it's the Gametrailers one.
Conclusion: If you really just couldn't get into the other Prime games at all due to the amount of exploration, you probably still won't like this one. If you thought the games could be great if they just made it a little easier to get around and upped the amount of combat, then you should love this one. However, it is a Metroid Prime game in every way, so don't expect Halo.
Naznatips's score for the first few hours of the game: 9.5. It would be a bit higher, but there is a bit too much combat in the beginning. However, I understand this is really meant as a tutorial for people so I am just nitpicking. I'm off to play some more!
